<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #shiny-shadow {
      display: flex;
      align-items: center;
      justify-content: center;
      height: 100vh;
      background: #1c2541;
    }

    button {
      border: 2px solid white;
      background: transparent;
      text-transform: uppercase;
      color: white;
      padding: 15px 50px;
      outline: none;
      overflow: hidden;
      position: relative;
    }

    span {
      z-index: 20;
    }

    button:after {
      content: '';
      display: block;
      position: absolute;
      top: -36px;
      left: -100px;
      background: white;
      width: 50px;
      height: 125px;
      opacity: 20%;
      transform: rotate(-45deg);
    }

    button:hover:after {
      left: 120%;
      transition: all 600ms cubic-bezier(0.3, 1, 0.2, 1);
      -webkit-transition: all 600ms cubic-bezier(0.3, 1, 0.2, 1);
    }
  </style>
</head>

<body>
  <div id="shiny-shadow">
    <button><span>Hover me</span></button>
  </div>
</body>

</html>